After Tuesday's midterm election leaders of the usually dominant Texas GOP are pondering how long the party will be on top.

Close statewide contests, including the race for Senate, and numerous defeats down-ballot stunned the GOP, which usually wins easily in midterm elections.

"We're in the process of trying to understand it a little bit better," said Sen. John Cornyn during a stop at the North Texas Food Bank in Plano. "It was an incredible confluence of events. One of them was a very charismatic candidate for the U.S. Senate who more than doubled his fundraising over what Sen. Cruz was able to do. Doing that against an incumbent Republican in a red state is unheard of."

Cornyn said Texas was still a red state but that the 2018 midterm elections should be a source of concern.

"I don't know whether this is a once-in-a-lifetime confluence of events or whether this represents something of a new normal," he said. "It is a wake-up call. We're thinking though this. We're going to try to be prepared for 2020. We're all very proud of what we've accomplished here in Texas."

Cornyn has a personal stake in 2020, since he said he will be running for re-election.

And in down-ballot races, there was all kinds of GOP carnage. Democrats won at least 12 statehouse races, two state Senate contests and two congressional seats. In Dallas County, Pete Sessions, the longtime Republican incumbent and chairman of the House Rules Committee, lost to first-time candidate Colin Allred.

What should be particularly disturbing is Democratic performance in counties long dominated by Republicans. In Collin County, state Senate candidate Angela Paxton (wife of Ken Paxton) won by a narrow margin, and state Reps. Matt Shaheen and Jeff Leach of Plano, who usually dominate, had tough re-election bids. Senate hopeful Beto O'Rourke carried Tarrant County, and he had 46 percent of the vote in Collin County.

Developing a general election message

Dave Carney, the chief political consultant for Abbott, acknowledged the losses for down-ballot Republicans and the close calls for others near the top of the ticket. He said some Republican candidates, after years of GOP dominance, were stuck in primary election mode, where the issues and tone are different from the general election.

"It's very difficult when your whole political career you've been in a different mindset and then you have to win voters outside of your comfort zone," Carney said. "You have to have a message that resonates beyond the March primaries."

Texas Gov. Greg Abbott posed for a photo with a supporter during the Texas GOP election night party at Brazos Hall in Austin, Texas, on Tuesday, Nov. 6, 2018. Abbott soundly defeated Lupe Valdez in his re-election bid.

(Nick Wagner/Austin American-Statesman)

Abbott, the only Republican statewide candidate with a voter turnout machine, stressed issues like property tax relief, more money for teachers and public safety during the general election. He had an easy time with former Dallas County Sheriff Lupe Valdez and got more votes than any candidate in the country, though he failed to match the 20 percentage point victory he had in 2014 over former state Sen. Wendy Davis.

Candidates from both parties typically retreat to their bases during primaries and then inch toward the center for general elections. That can be difficult, particularly when Republican primary voters often require red-meat issues like the so-called bathroom bill that critics said would have discriminated against transgender residents, or a hard-line approach to immigration.

"You have to build your own brand," Carney said. "It's about talking about the issues and real solutions."

For decades statewide Republicans haven't had to worry about finessing their messages, leaving that problem to Republicans in urban areas like Dallas County.

But Tuesday's results signal that hard-liners from both parties could be in trouble.

In Dallas County, five Republicans lost House races, including three incumbents. Two other Republicans in what were safe district barely won.

State Sen. Don Huffines of Dallas and Konni Burton of Colleyville, both considered extremely conservative, lost elections in Republican-leaning districts that are usually won in midterm contests. And state Rep. Ron Simmons, in usually reliably red southern Denton County, lost to Democrat Michelle Beckley.

"It's a new day in Texas politics," said Republican political consultant Bill Miller. "The old way of doing things, just focusing on the extreme elements of the base, consider that nostalgia. That day is gone."

The O'Rourke/Cruz effect

The wild card in the Texas midterm elections was O'Rourke, whose prolific fundraising and close finish against Cruz set the tone for candidates up and down the ballot. At the top of the ticket, he delivered for Democrats in races throughout Texas.

New voters here to stay

Going forward, analysts say the Republicans will have to adjust to Texas politics that will include a new crop of voters and an expanded general electorate. The 2020 elections could bring another record number of voters, particularly if President Donald Trump is on the ballot. Trump is a motivating factor for his critics and supporters.

Thousands of supporters attended an election night party for U.S. Senate candidate Rep. Beto O'Rourke at Southwest University Park on Nov. 06, 2018, in El Paso.

(Chip Somodevilla/Getty Images)

"This is a new era for voter participation that will only continue to thrive," Eppstein said. "Rural Texas will be redder, urban Texas bluer and suburban Texas is turning purple."

Cornyn said all elected officials needed to reassess their connections with voters.

"Tone is always important," he said. "We need to do a better job of listening to what's on people's minds and what their concerns are because this was a wake-up call."